Portable shredding machine



FIG. 1 is a front perspective view of a portable shredding machine, showing our new design, the broken line showing of the tires is for illustrative purposes only, and forms no part of the claimed design;

FIG. 2 is a right side elevational view;

FIG. 3 is a rear plan view;

FIG. 4 is a left side elevational view;

FIG. 5 is a front plan view; and,

FIG. 6 is a top plan view thereof. 

The ornamental design for a portable shredding machine, as shown and described. 